From 868d94fcb4769ad3a5d826c9f5483376433da8a5 Mon Sep 17 00:00:00 2001
From: "Lori A. Burns" <lori.burns@gmail.com>
Date: Tue, 11 Jun 2019 16:05:00 -0400
Subject: [PATCH] Apply c++ standard flag only to files of CXX language.
 (#1678)

---
 tools/pybind11Config.cmake.in | 6 +++++-
 tools/pybind11Tools.cmake     | 6 +++++-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/tools/pybind11Config.cmake.in b/tools/pybind11Config.cmake.in
index 3dd1b2c1a..8a7272ff9 100644
--- a/tools/pybind11Config.cmake.in
+++ b/tools/pybind11Config.cmake.in
@@ -90,7 +90,11 @@ if(NOT TARGET ${PN}::pybind11)
       set_property(TARGET ${PN}::module APPEND PROPERTY INTERFACE_LINK_LIBRARIES ${PYTHON_LIBRARIES})
     endif()
 
-    set_property(TARGET ${PN}::pybind11 APPEND PROPERTY INTERFACE_COMPILE_OPTIONS "${PYBIND11_CPP_STANDARD}")
+    if(CMAKE_VERSION VERSION_LESS 3.3)
+      set_property(TARGET ${PN}::pybind11 APPEND PROPERTY INTERFACE_COMPILE_OPTIONS "${PYBIND11_CPP_STANDARD}")
+    else()
+      set_property(TARGET ${PN}::pybind11 APPEND PROPERTY INTERFACE_COMPILE_OPTIONS $<$<COMPILE_LANGUAGE:CXX>:${PYBIND11_CPP_STANDARD}>)
+    endif()
 
     get_property(_iid TARGET ${PN}::pybind11 PROPERTY INTERFACE_INCLUDE_DIRECTORIES)
     get_property(_ill TARGET ${PN}::module PROPERTY INTERFACE_LINK_LIBRARIES)
diff --git a/tools/pybind11Tools.cmake b/tools/pybind11Tools.cmake
index ab8bf6270..e3ec572b5 100644
--- a/tools/pybind11Tools.cmake
+++ b/tools/pybind11Tools.cmake
@@ -185,7 +185,11 @@ function(pybind11_add_module target_name)
   endif()
 
   # Make sure C++11/14 are enabled
-  target_compile_options(${target_name} PUBLIC ${PYBIND11_CPP_STANDARD})
+  if(CMAKE_VERSION VERSION_LESS 3.3)
+    target_compile_options(${target_name} PUBLIC ${PYBIND11_CPP_STANDARD})
+  else()
+    target_compile_options(${target_name} PUBLIC $<$<COMPILE_LANGUAGE:CXX>:${PYBIND11_CPP_STANDARD}>)
+  endif()
 
   if(ARG_NO_EXTRAS)
     return()